Let a= {1, 3, 4}, b= { x| x is an even whole number less than 9}, c= {2, 5, 7, 10}, and d= { x| x is an odd whole number less than 10} 11. a u c 13. b u c 17. a n c answer. i need to know. you < 3

Answer to problem 11 is the set {1, 2, 3, 4, 5, 7, 10}

Answer to problem 13 is the set {2, 4, 5, 6, 7, 8, 10}

Answer to problem 17 is the empty set { } (see explanation below)

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Explanation to problem 11

Set A = {1, 3, 4}
Set C = {2, 5, 7, 10}

When we union these two sets together, we simply combine them writing all of the elements in one big set. This is why the answer is {1, 2, 3, 4, 5, 7, 10}

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Explanation to problem 13

B = {x|x is an even whole number less than 9}
B = {2, 4, 6, 8}
C = {2, 5, 7, 10}

Union B and C together and we get {2, 4, 5, 6, 7, 8, 10}

Toss out any duplicates

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Explanation to problem 17

The previous problems had us doing set unions. This time we're doing set intersections. We have these two sets
A = {1, 3, 4}
C = {2, 5, 7, 10}

The question is: what number is in BOTH set A and set C? The answer is "there is no such value"
1 is in A, but not in C
3 is in A, but not in C
4 is in A, but not in C
2 is in C, but not in A
5 is in C, but not in A
7 is in C, but not in A
10 is in C, but not in A
There are no overlapping values. No values are shared between the two sets

So the answer is simply "the empty set" which can be written as { }. This is a pair of curly brace with nothing inside them. Your book may use the special symbol , which is another way of saying "empty set"